ISLAMABAD (AP) — Pakistan's opposition on Friday said it found six spy-cameras at polling booths, hours before the senate was to elect a new chairman in the latest political test for Prime Minister Imran Khan's ruling party.

Speaking to reporters, Senator Mustafa Nawaz Khokhar, a lawmaker from the opposition Pakistan People’s Party, accused the intelligence agencies of installing the cameras to boost support for the government-backed candidates for chairman and deputy chairman.

Authorities ordered a probe into the incident and removed the devices, vote supervisor Senator Muzaffar Hussain Shah said in televised comments.

Pakistani opposition's newly elected Senator Yusuf Raza Gilani faces a tough contest against Sadiq Sanjrani, who is the outgoing chairman of the Senate.

The latest development comes days after the prime minister handily won a vote of confidence from the lower house, the National Assembly, but that was also just days after an embarrassing defeat for his ruling party’s key candidate in for Senate elections.